991226368008 has 84 divisors (see below), whose sum is σ = 2786763192765. Its totient is φ = 330383445408.

The previous prime is 991226368003. The next prime is 991226368037. The reversal of 991226368008 is 800863622199.

It is a powerful number, because all its prime factors have an exponent greater than 1 and also an Achilles number because it is not a perfect power.

It can be written as a sum of positive squares in 2 ways, for example, as 959220442404 + 32005925604 = 979398^2 + 178902^2 .

It is an ABA number since it can be written as A⋅B^A, here for A=2, B=703998.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is not an unprimeable number, because it can be changed into a prime (991226368003) by changing a digit.

It is a polite number, since it can be written in 20 ways as a sum of consecutive naturals, for example, 76025266 + ... + 76038302.

Almost surely, 2^991226368008 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 991226368008

991226368008 is an abundant number, since it is smaller than the sum of its proper divisors (1795536824757).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

991226368008 is an frugal number, since it uses more digits than its factorization.

991226368008 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 26098 (or 13042 counting only the distinct ones).

The product of its (nonzero) digits is 2239488, while the sum is 54.

The spelling of 991226368008 in words is "nine hundred ninety-one billion, two hundred twenty-six million, three hundred sixty-eight thousand, eight".